Hasil untuk "Balance of trade"

Hong-Nhat Hoang, Kien Nguyen, Hiroo Sekiya et al.

Confirmed uplinks in LoRaWAN improve reliability by requiring acknowledgment feedback from the network. However, gateway constraints such as half-duplex operation and duty-cycle limitations often prevent timely acknowledgment delivery, triggering retransmissions and degrading performance. These challenges are compounded in multi-gateway deployments, where overlapping coverage, correlated reception, and spatial interference create tightly coupled uplink-downlink dynamics. While prior analytical models capture parts of this behavior, a unified framework that jointly accounts for multi-gateway topology, heterogeneous bi-directional traffic, and spatial interference remains limited. In this paper, we propose a Unified Spatial Analytical Framework for confirmed-uplinks in multi-gateway LoRaWAN under percentage-based duty-cycle constraints. The framework serves as a fast and scalable what-if diagnostic engine for network planning and configuration. It combines a hex-cell spatial abstraction with imperfect spreading-factor orthogonality and heterogeneous traffic classes (NAPP/PAPP/CAPP), and couples these with a bi-directional M/G/1/1 renewal model to capture gateway transmission availability. Validation against NS-3 shows high fidelity in predicting key performance indicators (uplink success, downlink success, and retransmission overhead), with errors below 10% at fine spatial resolution. Finally, diagnostic case studies reveal that performance collapse is primarily driven by downlink capacity starvation (rather than uplink collisions) and expose the limitation regimes and fairness trade-offs of representative mitigation levers, including load-balance downlink assignment, gateway densification, and downlink airtime reduction.

Lacour M. Ayompe, Benis N. Egoh, Benis N. Egoh

Renewable energy systems (RES) are essential for combating climate change and achieving sustainable development. However, their deployment presents both ecological and socio-economic challenges. This review examines the impacts of renewable energy technologies on ecosystem services, focusing on the environmental footprints of solar PV, concentrating solar power, wind, hydropower, and biomass systems. It explores the socio-economic benefits, such as job creation and improved public health, and emphasizes the importance of effective policy frameworks in facilitating renewable energy adoption. Additionally, the need for integrating ecological considerations into energy planning to mitigate negative impacts is highlighted. Despite the clear benefits, research gaps persist, particularly in understanding the interactions between RES and ecosystem services. Future studies should prioritize comprehensive data collection, long-term monitoring, and adaptive management strategies. Addressing these critical knowledge voids is pivotal for optimizing the trade-offs between energy security and ecological integrity, offering a foundation for evidence-based policy formulation. By addressing these gaps, stakeholders can develop more sustainable energy practices that balance ecological integrity and community wellbeing, contributing to a sustainable and equitable energy future.

É. Vignon, É. Vignon, N. Chiabrando et al.

<p>Recent regional model findings suggest that the aeolian erosion of surface snow is a significant contribution to the overall Antarctic surface mass balance (SMB) through ice crystals sublimation and export outside of the ice sheet. Such findings raise the question of the relevance of accounting for such a process also in global climate models. This study presents the development of an intermediate-complexity parameterisation of blowing snow for the ICOLMDZ atmospheric general circulation model, the atmospheric component of the IPSL Coupled Model. The parameterisation is designed to be a trade-off between physical complexity and applicability in a general circulation model, with constraints on numerical cost and stability. The parameterisation is evaluated with in situ observations using limited-area simulations over Adélie Land. The model exhibits satisfactory results in terms of summer wind speed, temperature and intensity of blowing snow fluxes. In winter, blowing snow intensity and occurrences are overestimated close to the coast, concurring with a positive wind speed bias. In terms of blowing snow occurrences throughout the year, ICOLMDZ exhibits comparable performance with the regional atmospheric model MAR. Boundary-layer moistening and cooling as well as changes in surface radiative fluxes due to blowing snow crystals are also quantified in the simulations. Global simulations at standard global climate model resolution are carried out to investigate how the Antarctic SMB is modified with the activation of the blowing snow parameterisation. Results show an overall decrease of the net snow accumulation in the escarpment region due to surface snow erosion and an increase along the coast due to blowing snow deposition and increase in precipitation.</p>

Harry Aytug

Two decades of research on the euro's trade effects have produced estimates ranging from 4% to 30%, with no consensus on the magnitude. We find evidence that this divergence may reflect genuine heterogeneity in the euro's trade effect across country pairs rather than methodological differences alone. Using Eurostat data on 15 EU countries (12 eurozone members plus Denmark, Sweden, and the UK as controls) from 1995-2015, we estimate that euro adoption increased bilateral trade by 29% on average (14.1% after fixed effects correction), but effects range from -12% to +79% across eurozone pairs. Core eurozone pairs (e.g., Germany-France, Germany-Netherlands) show large gains, while peripheral pairs involving Finland, Greece, and Portugal saw smaller or negative effects, with some negative estimates statistically significant and interpretable as trade diversion. Pre-euro trade intensity and GDP account for over 90% of feature importance in explaining this heterogeneity. Extending to EU28, we find evidence that crisis-era adopters (Slovakia, Estonia, Latvia) pull down naive estimates to 4.3%, but accounting for fixed effects recovers estimates of 13.4%, consistent with the EU15 fixed-effects baseline of 14.1%. Illustrative counterfactual analysis suggests non-eurozone members would have experienced varied effects: UK (+33%), Sweden (+22%), Denmark (+19%). The wide range of prior estimates appears to be largely a feature of the data, not a bug in the methods.

Alejandra Martinez

I study how firms adjust to temporary disruptions in international trade relationships organized through relational contracts. I exploit an extreme, plausibly exogenous weather shock during the 2010-11 La Niña season that restricted Colombian flower exporters' access to cargo terminals. Using transaction-level data from the Colombian-U.S. flower trade, I show that importers with less-exposed supplier portfolios are less likely to terminate disrupted relationships, instead tolerating shipment delays. In contrast, firms facing greater exposure experience higher partner turnover and are more likely to exit the market, with exit accounting for a substantial share of relationship separations. These findings demonstrate that idiosyncratic shocks to buyer-seller relationships can propagate into persistent changes in firms' trading portfolios.

Ilias Alexandros Parmaksizoglou, Alessandro Bombelli, Alexei Sharpanskykh

<i>Background:</i> The rapid growth of international maritime trade has intensified operational challenges at marine terminals due to increased interaction between vessels, trucks, and trains. Key issues include berth congestion, inefficient truck arrivals, and underutilization of terminal resources. Ensuring coordinated planning among transport modes and fostering collaboration between stakeholders such as vessel operators, logistics providers, and terminal managers is critical to mitigating these inefficiencies. <i>Methods:</i> This study proposes a multi-agent, multi-objective coordination model that synchronizes vessel berth allocation with truck appointment scheduling. A solution method combining prioritized planning with a neighborhood search heuristic is introduced to explore Pareto-optimal trade-offs. The performance of this approach is benchmarked against well-established multi-objective evolutionary algorithms (MOEAs), including NSGA-II and SPEA2. <i>Results:</i> Numerical experiments demonstrate that the proposed method generates a greater number of Pareto-optimal solutions and achieves higher hypervolume indicators compared to MOEAs. These results show improved balance among objectives such as minimizing vessel waiting times, reducing truck congestion, and optimizing terminal resource usage. <i>Conclusions:</i> By integrating berth allocation and truck scheduling through a transparent, multi-agent approach, this work provides decision-makers with better tools to evaluate trade-offs in port terminal operations. The proposed strategy supports more efficient, fair, and informed coordination in complex multimodal environments.

G. Ducros, T. Tiggeloven, T. Tiggeloven et al.

<p>In the summer of 2018, large parts of Scandinavia faced record-breaking heat and drought, leading to increased mortality, agricultural water shortages, hydropower deficits, and higher energy prices. The 2018 heatwave coupled with droughts leading to wildfires are described as multi-hazard events, defined as compounding, cascading or consecutive events. Climate change is driving an increase in heat-related events and, subsequently, shows the necessity to prepare for such hazards, and to assess suitable mitigation strategies. To better understand the interplay of heatwaves, droughts, and wildfires across sectors, and to support disaster risk management in multi-hazard settings, we analyze their occurrence in Scandinavia using a spatial assessment of compound events. To assess their potential direct and indirect economic impacts we use the global Computable General Equilibrium (CGE) model GRACE (Global Responses to Anthropogenic Changes in the Environment) and the 2018 heatwave-drought period as a baseline to map multi-hazard risk. We find that multi-hazard events are pronounced in the summer months in Scandinavia and the 2018 multi-hazard events did not occur in isolation. The 2018 multi-hazard events led to a 0.08 % GDP drop in Scandinavia, with forestry experiencing a 3.04 % decline, affecting agriculture, electricity, and forestry exports, which dropped by 29.39 %, impacting Europe's trade balance. This research shows the importance of ripple effects of multi-hazards, specifically compound heatwave, drought and wildfire, and that forest management and a better understanding of their direct and indirect societal impacts are vital to reducing the risks of heat-related multi-hazards in vulnerable areas.</p>

Michelena Gabriel, Ernst Christoph, Pablo Bertin

This paper assesses the global employment and trade effects of renewed tariff escalation following the reintroduction of the United States' America First strategy in 2025. Using a multiregional input-output (MRIO) framework integrated with a trade model, the analysis captures endogenous adjustments in bilateral trade shares and final demand in response to changes in prices and competitiveness. Three scenarios are simulated to reflect alternative configurations of trade policy: existing tariffs without retaliation, updated tariffs including retaliatory measures, and a potential scenario characterized by de-escalation of the trade conflict. The results indicate that tariff increases generate widespread employment and export losses, with cumulative global job declines exceeding 23 million in the most adverse scenario. Informal and low-skilled workers bear the largest burden, accounting for more than 80 percent of total employment losses, while high-income and upper middle-income countries experience significant contractions in export volumes.

Junaid ur Rehman

We consider an example scenario where we require several copies of a pure quantum state $|ψ\rangle$ for some quantum information processing task. Due to practical limitations, we only have access to $N = 10^3$ depolarized copies of $|ψ\rangle$ such that the fidelity $F$ of each copy with $|ψ\rangle$ is $0.75$. We denote this quantum asset with the ensemble $\mathcal{A}: (10^3, 0.75)_{|ψ\rangle}$. A genie appears and offers to trade $\mathcal{A}$ with either $\mathcal{B}: (10^4, 0.65)_{|ψ\rangle}$ or with $\mathcal{C}: (10^2, 0.90)_{|ψ\rangle}$. Should we accept the trade with either of these two ensembles? In this article, we attempt to answer this question with arbitrary $N$ and $F$. More specifically, we derive resource equivalence curves from quantum resource theory of purity, quantum state distinguishability, quantum state purification, and quantum state tomography. These curves enable ranking of these ensembles according to their operational usefulness for these tasks and allow us to answer the question of trading the aforementioned ensembles.

Houshuang Chen, Yaonan Jin, Pinyan Lu et al.

We examine fixed-price mechanisms in bilateral trade through the lens of regret minimization. Our main results are twofold. (i) For independent values, a near-optimal $\widetildeΘ(T^{2/3})$ tight bound for $\textsf{Global Budget Balance}$ fixed-price mechanisms with two-bit/one-bit feedback. (ii) For correlated/adversarial values, a near-optimal $Ω(T^{3/4})$ lower bound for $\textsf{Global Budget Balance}$ fixed-price mechanisms with two-bit/one-bit feedback, which improves the best known $Ω(T^{5/7})$ lower bound obtained in the work [BCCF24] and, up to polylogarithmic factors, matches the $\widetilde{\mathcal{O}}(T^{3 / 4})$ upper bound obtained in the same work. Our work in combination with the previous works [CCCFL24mor, CCCFL24jmlr, AFF24, BCCF24] (essentially) gives a thorough understanding of regret minimization for fixed-price bilateral trade. En route, we have developed two technical ingredients that might be of independent interest: (i) A novel algorithmic paradigm, called $\textit{fractal elimination}$, to address one-bit feedback and independent values. (ii) A new $\textit{lower-bound construction}$ with novel proof techniques, to address the $\textsf{Global Budget Balance}$ constraint and correlated values.

Megan S. Adams, Taal Levi, Mathieu Bourbonnais et al.

Abstract Wildlife must increasingly balance trade‐offs between the need to access important foods and the mortality risks associated with human‐dominated landscapes. Human disturbance can profoundly influence wildlife behavior, but managers know little about the relationship between disturbance–behavior dynamics and associated consequences for foraging. We address this gap by empirically investigating the consequences of human activity on a keystone predator–prey interaction in a region with limited but varied industrial disturbance. Using stable isotope data from 226 hair samples of grizzly bears (Ursus arctos horribilis) collected from 1995 to 2014 across 22 salmon‐bearing watersheds (88,000 km2) in British Columbia, Canada, we examined how human activity influenced their consumption of spawning salmon (Oncorhynchus spp.), a fitness‐related food. Accounting for the abundance of salmon and other foods, salmon consumption strongly decreased (up to 59% for females) with increasing human disturbance (as measured by the human footprint index) in riparian zones of salmon‐bearing rivers. Declines in salmon consumption occurred with disturbance even in watersheds with low footprints. In a region currently among the least influenced by industrial activity, intensification of disturbance in river valleys is predicted to increasingly decouple bears from salmon, possibly driving associated reductions in population productivity and provisioning of salmon nutrients to terrestrial ecosystems. Accordingly, we draw on our results to make landscape‐scale and access‐related management recommendations beyond current streamside protection buffers. This work illustrates the interaction between habitat modification and food security for wildlife, highlighting the potential for unacknowledged interactions and cumulative effects in increasingly modified landscapes.

Syafaat Muhari, Zulfiqar Ali Jumani

There was no consensus on how to deal with the trade-off between maintaining sustainability and outreach of microfinance institutions among researchers. This research aims to find out how Islamic rural banks balance the demands for sustainability and financial outreach at the same time where competition in the microfinance segment is increasing. The paper provides time series data which includes monthly industry data from Islamic Rural Bank for a period of more than 14 years starting from January 2009 to March 2023. In the first analysis, an estimate of the level of market competition is computed by the Lerner Index (LI) of each period. Furthermore, the efficiency analysis of Data Envelopment Analysis (DEA) is used to measure efficiency which allows estimation of efficiency performance using multiple inputs and outputs to understand how Islamic Rural Bank deals with sustainability and outreach. Finally, a Vector Autoregression/Vector Error Correction Model (VAR/VECM) analysis is used to analyse the relationship between the level of market competition and the efficiency of Islamic Rural Bank in achieving sustainability and outreach objectives. The results of the study suggest that by using a production approach, Islamic Rural Bank can operate efficiently while maintaining sustainability and outreach objectives without trade-offs. In addition, market competition has a moderate influence on achieving sustainability goals and their outreach. This research examines how Islamic Rural Bank is one of the microfinances to overcome the trade-off between the goals among high competition and the increasing financial needs of customers. The Microfinance model from Islamic Rural Banks can be replicated in other microfinance institutions (MFIs) to reach both outreach and sustainability goals.

XIAO Zijian, Chen-Chun Hsia, XU Yanggang et al.

Active search with unmanned aerial vehicle (UAV) swarms in cluttered and unpredictable environments poses a critical challenge in search and rescue missions, where the rapid localizations of survivors are of paramount importance, as the majority of urban disaster victims are surface casualties. However, the altitude-dependent sensor performance of UAV introduces a crucial trade-off between coverage and accuracy, significantly influencing the coordination and decision-making of UAV swarms. The optimal strategy has to strike a balance between exploring larger areas at higher altitudes and exploiting regions of high target probability at lower altitudes. To address these challenges, collaborative altitude-adaptive reinforcement learning (CARL) was proposed which incorporated an altitude-aware sensor model, a confidence-informed assessment module, and an altitude-adaptive planner based on proximal policy optimization (PPO) algorithms. CARL enabled UAV to dynamically adjust their sensing location and made informed decisions. Furthermore, a tailored reward shaping strategy was introduced, which maximized search efficiency in extensive environments. Comprehensive simulations under diverse conditions demonstrate that CARL surpasses baseline methods, achieves a 12% improvement in full recovery rate, and showcase its potential for enhancing the effectiveness of UAV swarms in active search missions.

Chuan-Feng Xu, Peng-Cheng Liu, Jason W. Chapman et al.

Striking a trade-off between migration and reproduction becomes imperative during long-range migration to ensure proper energy allocation. However, the mechanisms involved in this trade-off remain poorly understood. Here, we used a takeoff assay to distinguish migratory from non-migratory individuals in the fall armyworm, which is a major migratory insect worldwide. Migratory females displayed delayed ovarian development and flew further and faster than non-migratory females during tethered flight. Transcriptome analyses demonstrated an enrichment of fatty acid genes across successive levels of ovarian development and different migratory behaviors. Additionally, genes with roles in phototransduction and carbohydrate digestion along with absorption function were enriched in migratory females. Consistent with this, we identified increased abdominal lipids in migratory females that were mobilized to supply energy to the flight muscles in the thorax. Our study reveals that the fall armyworm faces a trade-off in allocating abdominal triglycerides between migration and reproduction during flight. The findings provide valuable insights for future research on this trade-off and highlight the key energy components involved in this strategic balance.

Moshe Babaioff, Amitai Frey, Noam Nisan

We study the problem of designing a two-sided market (double auction) to maximize the gains from trade (social welfare) under the constraints of (dominant-strategy) incentive compatibility and budget-balance. Our goal is to do so for an unknown distribution from which we are given a polynomial number of samples. Our first result is a general impossibility for the case of correlated distributions of values even between just one seller and two buyers, in contrast to the case of one seller and one buyer (bilateral trade) where this is possible. Our second result is an efficient learning algorithm for one seller and two buyers in the case of independent distributions which is based on a novel algorithm for computing optimal mechanisms for finitely supported and explicitly given independent distributions. Both results rely heavily on characterizations of (dominant-strategy) incentive compatible mechanisms that are strongly budget-balanced.

Xinming Du, Lei Li, Eric Zou

This paper shows a cascading mechanism through which international trade-induced deforestation results in a decline of health outcomes in cities distant from where trade activities occur. We examine Brazil, which has ramped up agricultural export over the last two decades to meet rising global demand. Using a shift-share research design, we first show that export shocks cause substantial local agricultural expansion and a virtual one-for-one decline in forest cover. We then construct a dynamic area-of-effect model that predicts where atmospheric changes should be felt - due to loss of forests that would otherwise serve to filter out and absorb air pollutants as they travel - downwind of the deforestation areas. Leveraging quasi-random variation in these atmospheric connections, we establish a causal link between deforestation upstream and subsequent rises in air pollution and premature deaths downstream, with the mortality effects predominantly driven by cardiovascular and respiratory causes. Our estimates reveal a large telecoupled health externality of trade deforestation: over 700,000 premature deaths in Brazil over the past two decades. This equates to $0.18 loss in statistical life value per $1 agricultural exports over the study period.

Matthew I. Jones

We introduce a new framework to study the group dynamics and game-theoretic considerations when voters in a committee are allowed to trade votes. This model represents a significant step forward by considering vote-for-vote trades in a low-information environment where voters do not know the preferences of their trading partners. All voters draw their preference intensities on two issues from a common probability distribution and then consider offering to trade with an anonymous partner. The result is a strategic game between two voters that can be studied analytically. We compute the Nash equilibria for this game and derive several interesting results involving symmetry, group heterogeneity, and more. This framework allows us to determine that trades are typically detrimental to the welfare of the group as a whole, but there are exceptions. We also expand our model to allow all voters to trade votes and derive approximate results for this more general scenario. Finally, we emulate vote trading in real groups by forming simulated committees using real voter preference intensity data and computing the resulting equilibria and associated welfare gains or losses.

Xiangzheng Deng, Zhihui Li, J. Gibson

Kalina B. Manova, Zhihong Yu

The fragmentation of production across borders allows firms to make and export final goods, or to perform only intermediate stages of production by processing imported inputs for re-exporting. We examine how financial frictions affect companies' choice between processing and ordinary trade – implicitly a choice of production technology and position in global supply chains – and how this decision affects performance. We exploit matched customs and balance sheet data from China, where exports are classified as ordinary trade, import-and-assembly processing trade (processing firm sources and pays for imported inputs), and pure assembly processing trade (processing firm receives foreign inputs for free). Value added, profits, and profitability rise from pure assembly to processing with imports to ordinary trade. However, more profitable trade regimes require more working capital because they entail higher up-front costs. As a result, credit constraints induce firms to conduct more processing trade and pure assembly in particular and preclude them from pursuing higher value-added, more profitable activities. Financial market imperfections thus impact the organization of production across firms and countries and inform optimal trade and development policy in the presence of global production networks.

Junqi Chen, Yong Wang, Miao Ye et al.

Fueled by the explosive growth of edge smart IoT devices, edge storage systems (ESS) have emerged as a new paradigm to support the efficient access of massive edge data. ESS can greatly alleviate the burden of cloud center and enhance the Quality of Experience (QoE) for users. However, despite the remarkable progress of ESS, it still faces the challenges of how to improve the systems fault tolerance ability and efficiency. Therefore, designing a secure and efficient text fault-tolerant storage scheme is urgent and indispensable. Unfortunately, existing text fault-tolerant schemes for ESS still retain various drawbacks, including: high edge storage overhead, hard to protect the edge data privacy and low data writing performance. Motivated by this, we propose a secure text cloud-edge collaborative fault-tolerant storage scheme and its data writing optimization method. Precisely, we first propose a Hierarchical text Cloud-Edge Collaborative Fault-Tolerant Storage (HCEFT) model to achieve system robustness, low edge storage overhead, and edge data privacy security. We further optimized the writing process of HCEFT by designing a data writing optimization method called ECWSS (Erasure Code data Writing method based on Steiner tree and SDN) to achieve a better text trade-off between the data writing time and traffic consumption. Finally, Comprehensive comparison and extensive experiments show that our scheme can achieve better data robustness, availability and security. Moreover, the writing optimization method can reduce 13&#x0025;-67&#x0025; data write time and 20&#x0025;-62&#x0025; network traffic consumption while providing better network load balance performance.